Another Reason to Use an Ad Blocker: Malvertising Has Tripled This Year

It's dangerous to go online alone.

Proponents of ad-blocking software may have another reason to continue blocking ads.

A new report from cybersecurity firm Cyphort published this morning notes that instances of malware served via online advertising networks increased 325 percent between June 2014 and February of this year. The report notes that several high-profile websites, including the Forbes, Huffington Post, and LA Weekly, served malware via their ads in that time frame.

Spreading malicious software, or malware, via online advertising networks is commonly referred to as "malvertising," and, according to Cyphort, is seen by cybercriminals as being particularly effective because compromised ads are visually indistinguishable from safe ads.

The process typically works as follows: Posing as benign advertisers, cybercriminals will initially seed advertising networks with safe ads in order to build trust with the networks and the websites that use these networks. They then periodically insert ads laden with malware, which then infect users' computers. Infected ads are typically Flash-based, which is partly why so many companies, including Mozilla and Amazon, are phasing out their support of Flash.

In the short term, Cyphort notes that infected ads can be blocked through the use of software like ad blockers like Adblock Plus and uBlock. Using ad blockers, of course, deprives websites of vital ad revenue, with a recent study pegging the amount of revenue lost because of ad blockers at $22 billion in 2015 so far.